1. Field of the Invention
Exemplary embodiments of the present invention relate to liquid crystal displays.
2. Description of the Related Art
Liquid crystal displays are among the most common type of flat panel displays. A liquid crystal display includes two display panels, where electric field generating electrodes, such as a pixel electrode and a common electrode are formed, and a liquid crystal layer interposed there between. A liquid crystal display generates an electric field in the liquid crystal layer, by applying a voltage to the electric field generating electrodes, to orient liquid crystal molecules of the liquid crystal layer, and controls polarization of incident light to thereby display an image.
A liquid crystal display also includes a switching element connected to each pixel electrode, and a plurality of signal lines including gate lines and data lines for applying the voltage to the pixel electrode, by controlling the switching element.
A liquid crystal display receives an input image signal from an external graphic controller. The input image signal contains luminance information for each pixel. Each luminance has a predetermined number. Each pixel is applied with a data voltage corresponding to a desired luminance. The data voltage applied to the pixel is represented as a pixel voltage, depending on a difference with a relative voltage. Each pixel displays a luminance that is embodied by the gray of the image signal, according to the pixel voltage. In this case, a pixel voltage range that the liquid crystal display can use is determined according to a driver.
Meanwhile, in order to apply the data voltage to each pixel electrode of the liquid crystal display, each pixel electrode is connected to the switching element. Since light is not transmitted from a location where the switching element is formed, a higher number of switching elements leads to a smaller aperture ratio for the liquid crystal display. Further, contact holes are formed to connect various signal transferring lines, which are formed on different layers, for transferring the signal to each pixel. Light is not transmitted through areas where the contact holes are formed. As a result, the contact holes decrease the aperture ratio of the liquid crystal display.
As the length of a signal line increases, the resistance of the signal line also increases, which leads to signal delays. As a result, display quality may be reduced.
The driver of a liquid crystal display is mounted directly on a display panel, in the form of a plurality of integrated circuit chips, or is mounted on a flexible circuit film attached to the display panel. The integrated circuit chip represents a significant portion of the manufacturing costs of a liquid crystal display. In particular, as the number of data lines increases, the cost of the driver of a liquid crystal display also increases.
In order to improve the display quality of a liquid crystal display, a liquid crystal display should have a high contrast ratio, an excellent optical viewing angle, and a high response speed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not constitute prior art.